1. Field of the Invention
The present invention relates to a vehicle headlamp in which a reflector serving as an inclinable member with a light source mounted thereon is supported by an aiming mechanism so that it is inclinable with respect to a lamp body serving as a reference member mounted on and fixed to a vehicle body or the like and, between the lamp body and reflector, an inclination measuring device is disposed for measuring the inclination of the reflector in the right and left direction thereof (that is, the inclination of the optical path of the lamp in the right and left direction thereof). More particularly, the invention relates to a vehicle headlamp in which a zero point adjustment operation portion of a zero point adjusting mechanism provided in the inclination measuring device is exposed to the outside of the lamp body serving as the reference member.
2. Related Art
As a structure for a headlamp of the above-mentioned type, conventionally, there has been known a structure as shown in FIGS. 19 and 20. That is, a reflector c with a light source b mounted thereon is supported by an aiming mechanism (which is composed of two aiming screws d, e and a ball joint f) to be inclinable with respect to a lamp body a mounted on and fixed to a vehicle body, and, if a rotation operation portion d.sub.1, e.sub.1 disposed on the rear end portion of an aiming screw projecting backwardly of the lamp body a is rotated, then the reflector c is inclined in the vertical direction as well as in the right and left direction thereof to thereby be able to adjust the position of the optical axis L of the lamp.
Between the lamp body a and reflector c, there is provided an inclination measuring device g including a slide member g.sub.1 which is slidable back and forth by an amount proportional to the amount of inclination of the reflector c, whereby the amount of inclination of the reflector c in the right and left direction thereof with respect to the reference position thereof is measured in accordance with the amount of displacement or sliding of the slide member g.sub.1 with a scale m added thereto. A zero point adjust screw h shown in FIG. 20 is formed in a cylindrical body with the slide member g.sub.1 stored in the interior portion thereof and projects backwardly of the lamp body a. If the zero point adjust screw h is rotated a scale zero point position in the inclination measuring device g is adjusted.
An inclination measuring device i consisting of a level which is mounted on the upper surface wall of the reflector c and is used to measure the amount of inclination of the reflector c in the vertical direction thereof with respect to the reference position thereof (that is, the amount of inclination of the optical axis L of the lamp in the vertical direction thereof). A zero point adjust screw j is provided in the inclination measuring device i.
Now, when putting a vehicle such as an automobile onto the market, the lamp is adjusted in such a manner that the optical axis L thereof is set at a proper position by the aiming mechanism (that is, the aiming screws d, e) and further the zero point position of the zero point adjust mechanism in the inclination measuring devices g, i is adjusted properly by the zero point adjust screws h, j, before the automobile is put onto the market. After that, if the optical axis L of the lamp is out of order for some reason or other, then indicators in the inclination measuring devices g, i indicate not the scale zero point but a value (a graduation) equivalent to the amount of displacement of the optical axis L and, therefore, if the aiming screws d, e are rotated to thereby adjust the inclination measuring devices g, i so that the indicators in the inclination measuring devices g, i can indicate the zero point, then the optical axis L of the lamp can be returned to the proper position.
However, in the above-mentioned conventional headlamp, since the zero point adjust screw h of the inclination measuring device g projects backwardly of the lamp body a, there is a fear that a user can rotate the zero point adjust screw h in error to thereby cause the scale zero point in the inclination measuring device g to be out of order, which makes it impossible not only to check whether the optical axis L of the lamp lies at its proper position or not, but also to make an aiming adjustment when the optical axis L of the lamp is out of order.